Always a tricky choice.
You might enquire about the Tandem Slimx2 pump to see when it is due in the UK.
It is being upgraded, software wise, for Dexcom CGM., including the stop infusion for low BSLs.
I think this upgrade has already happened in US, and is due here in Australia later this year.
As you will have noted the Omnipod has the separate device/controller and is not CGM compatible yet , The Roche is not CGM compatible yet and Medtronics run the own CGM version.
@tim2000s may know if the G6 can be linked unofficially to a Medtronics pump though !
Best Wishes.
I was diagnosed at age 13, 52 years ago, so let him know that he has a lot of dish-washing and other chores to do and plenty of time to perfect them !!